1. Field of the Invention
The present invention relates generally to bow presses for maintenance of archery bows, and more particularly, to a manual and electrically-powered compound bow press that lies outside of the radius of the bow and that compresses a compound bow from the ends of the bow limbs.
2. Description of the Related Art
Bow presses are used in maintenance of archery bows, and in particular, are necessary for the maintenance of compound bows, where the force required to compress the bow in order to remove the bow string(s) and perform other operations can require hundreds of pounds of force.
A typical shop-installed bow press has a form and operation such as that described in U.S. Pat. No. 6,968,834, in which the bow is stabilized at multiple points along its curvature and wherein the force applied to compress the bow is applied by a crank along the direction of the nock and perpendicular to the radius of curvature of the bow. The press is located outside of the curvature of the bow limbs, so that the bow press structure does not interfere with the operator's access to the bowstring and other components while working on the bow. Such bow presses require practice and training in order to properly compress a bow without damaging the riser or limbs. Some bow presses require adjustment of multiple jacks in order to start compressing a bow.
Other bow presses for field use such as those described in U.S. Pat. No. 7,089,923, provide a lightweight and highly portable structure that contracts a bow via tension applied from the inside of the curvature of the bow limbs, and only from the ends of the bow limbs, but the tensioning structure lies in or near the path of the bow string(s) and further is not designed to operated as a secured fixture, as is desirable for use in a bow maintenance shop environment.
It is highly desirable to contract a bow from the ends of the bow limbs, as devices such as that described in the above-referenced U.S. Pat. No. 6,968,834 must necessarily apply force to points along the riser of the bow and other points along the bow limbs other than the bow limb ends. Present-day compound bows are designed to be lightweight and are typically be made of ductile metals and/or fragile composites. In order to lighten such compound bows, as much material as possible is typically removed from the limbs and body of the bow, and such designs vary greatly from manufacturer to manufacturer. Therefore, there is no guarantee that any point along the bow will have sufficient structural strength or elasticity to tolerate a force applied at that point.
However, the ends of the limbs of a bow must be able to tolerate a force along the direction of the bow string at least equal to that applied by the bow string(s) at the point of maximum draw, as that force is applied to the bow in use. Therefore, compound bows typically will be strong at the bow limb ends and most certainly tolerant of a force applied along the direction of the bow string and cable at the bow limb ends, as that force is applied when the bow string is drawn.
Therefore, it would be desirable to provide a maintenance bow press, and in particular a press for compound bows, that contracts the bow by applying force only at the bow limb ends. It is further desirable to provide a bow press that is simple to use and requires little training or effort to service a compound bow without damaging the bow.